Two-Year Results of X-Stop Interspinous Implant for the Treatment of Lumbar Spinal Stenosis

STUDY DESIGN: Prospective Observational Study. OBJECTIVE: To prospectively assess the clinical outcome of patients treated for symptomatic spinal stenosis with the X-stop device. SUMMARY OF BACKGROUND DATA: The X-stop device is used in the treatment of symptomatic lumbar spinal stenosis. The preliminary results of this study of 40 patients at 1 year were published in 2007. The 2-year results of 57 patients are reported in this paper. Zucherman et al report 60% significant improvement at 1 year and 48.4% at 2 years. METHODS: Fifty-seven consecutive patients with radiologically confirmed lumbar spinal stenosis were enrolled and treated with the X-stop device. The device was implanted at a maximum of 2 affected levels. Clinical response was evaluated with the Zurich Claudication Questionnaire (ZCQ), Oswestry Disability Index, and Short Form-36 questionnaires preoperatively and 6, 12, and 24 months postoperatively. RESULTS: Of the 57 patients enrolled, 54 completed the ZCQ questionnaire at 1 year and 46 patients at 2 years. Clinically significant improvement was attained by 65% at 1 year and 57% at 2 years and 70% were satisfied with the outcome of the surgery. Single level and double level insertions did not have significant difference in clinical outcome. CONCLUSION: This study demonstrates with the use of ZCQ scores as primary outcome measures that improved clinical outcomes are maintained at 2 years after X-stop implantation.